Women are more likely to be infected with contagious yawning than men

Women are more likely than men to be infected by contagious yawning, a study has found. Researchers believe this may be a result of women having more developed empathic abilities.

Led by researchers at the University of Pisa, researchers collected data on yawn contagion (where a person yawning triggers you to yawn) over five years. They observed men and women in their natural environment, be it at the office, dinner or social events, with the individuals unaware they were being observed. Their relationship status was, however, known to the researchers.

Their findings, published in the Royal Society Open Science, collected data on spontaneous yawning (not triggered by someone else yawning) and contagious yawning (if the yawn was triggered by another person yawning within three minutes).

They found no major differences between the spontaneous yawn frequencies of men and women. However, contagious yawning was found to be significantly higher in women than in men. Furthermore, it was found to be lower when people were just acquaintances than between friends and family.

Scientists note this gender bias is also found in non-human species such as monkeys and apes. They say the findings fit in with the idea that empathic abilities are more developed in women than in men: "Because there is growing evidence that yawn contagion is an empathy-based phenomenon, we expect that the female bias in the empathic abilities reflects on a gender skew in the responsiveness to others' yawns," they wrote.

"These results not only confirm that yawn contagion is sensitive to social closeness, but also that the phenomenon is affected by the same gender bias affecting empathy. The sex skew, also found in other non-human species, fits with the female social roles which are likely to require higher empathic abilities (e.g. parental care, group cohesion maintenance, social mediation)."

Previous research into yawning and empathy found people with psychopathic characteristics are less likely to yawn contagiously than those with high levels of empathy. Brian Rundle, lead researcher of the study published in Personality and Individual Differences, said: "You may yawn, even if you don't have to. We all know it and always wonder why. I thought, 'If it's true that yawning is related to empathy, I'll bet that psychopaths yawn a lot less.' So I put it to the test.

"The take-home lesson is not that if you yawn and someone else doesn't, the other person is a psychopath. A lot of people didn't yawn, and we know that we're not very likely to yawn in response to a stranger we don't have empathetic connections with. But what we found tells us there is a neurological connection — some overlap — between psychopathy and contagious yawning. This is a good starting point to ask more questions."